Pigment binder of acrylate-acrylonitrile-methacrylic acid for paper coatings



The fo11ovving i1111Stfates the fepafation and a p1ica tioI1to papef ofa nunbeT of coating com oSitions accofding to the pfesent invention, andthe e1fect of vafious S11f face active agentS in inlpfoving the adheSiveaction of the copo1yTI1e1 in the coInpositions.

A11 an1n1oniated anionic copo1yITle1 lateX iS pfepafed aS foHowS.

(1) AqUeoUS phaSe= Deionized vvatef 97.8 EmU1SiefSodium di(1,3di

MiXtUfe 1 is chafged into a 3necked 1 1aSh l ltted with two TeseTvoiTs,Stiffef and Teux condenSef. 01ixtufe 1 iS heated to 90 with fapidStiffing and II11xt11feS 2 and 3 afe chaTged into the feSpectivefeSefvoiTS. of n1ix t11fe 1 is added over In1nute, and the Tenlaindef ofn1ixtUre 1 and 80% of n1ixtUfe 2 aTe added dTopWise oveT 2 houTS. TheTeII1aindef of Inixtufe 2 iS then added, and heating iS continued foTabout an houf, unti1 po1yT1efization iS coIT11)1ete. The TeS111tinglatex iS cooled to foon1 tompeTatnfe and its pH is Taised to 9.5 byadditio11 of con centfated (291) aqueous an1II1onia. It containS 44.3%copolyIner Solids by vveight.

A pigIlent diSpeTSion is pfepafed by fapidly agitating the fo11owi1gnixtnfes= and the 11na1 coating con1poSition is pfepafed by adding 169g. of the above descTibed 1atex thefeto to the pign1ent disperSion withcontinued agitation.

The Tesult is a coating color Which containS 63% tota1 solidS byvveight. The vveight Tatio clay:copolyITlef is substantially 7: 1.

The con1poSition is app1ied to standafd 50 1b. (25 x 38 /500 Team)coating TaW stock by Ineans of a Bifd 1aboratofy appHcatof having anofifice of SUic1ent Width to deposit a coating having a vveight of 151b. pef TeaIn. The coated sheetS afe dfied in ait at TooIn teT1pefatue,ovendIied fof thfee n1inutes at 210 F. and afe then calendefed.

The pfoceduTe is fepeated except that othe1 Sin^lilaf co o1yfneT1aticesafe USed aS Shown in the table be1ow.

The adheSiveneSS of the po1ynJef on the coated papef towards the paperand tovvafdS the pigment iS detennined by the Standafd I.G.T. (InStitUutvoof (1fa11Sche Tech- Iliek) test, Whefein 3. stfip of the coated papefundef teSt iS C1aInped to a To11 and is fotated at an increaSing fate ofSpeed againSt a stee1 Toner caffying a tacky b1ack ink. The point offailufe of the coating iS the speed at vhich the tacky ink pu11s specksof the coating ffoII1 the papef (01 I111lS Specks of pigfIlent ffon1 thecoating).

I1I1 o. 1Iononler SodinI S111fosI1cciIlate 1 iok 1eatio En1u1SieTSistance 1 1 19 :1 Di(1.3di11ethy1)buty1 485 2 79:19:2 do 545 3 S4:14:2dO 675 83:14:3 d0 600 89: 0:2 do 505 90: 9:1 do 350 8:1:2 Di(2ethylhexy518 81:14:2 ])i(1-InethylbutyD 405 1 ect pcr I11inute at 'hioh pickingof the coating fiTst ocors (X1th No. 4 ink in I.G.T. teSt).

We clain1= 1. A 11I1id aqueous anln1onfated pigInent coating coInposition fo1 VvateTlaid cellu1oSe vebS, Which conSiSts eS- sentia11y ofa llnifofn1 suS enSion of a hydTophi1ic inof ganic Ininefa1 )igInent aScoating conlponent in a latex of a hydTophobic ofganic snbStantiany 7595:424:13 peTCent by veight ethy1 acfylate:acry1onitfile:n1ethacrylic acidcopo1ynlef aS adheSive coInponent thefefof, and S11f- 1icientan1fnoniun1 hydFoxide to give said con1 OSition a pH of at leaSt 9, theweight of Said pigInent boing 5 to 20 tiI1eS the vveight of saidpolyn1ef.

2. A conlposition accoTding to claiIn 1 Vhefein the el ative aInountS ofthe constituentS of said copolynlef afe Chosen So aS to be TepfeSentedby ara1le1ogfaf1 EFGH of the anneXed dTaWing.

3. A con1 osition according to c1ain1 1 Wherein the Telative aIT1ollntsof the constituents of said polyn1ef afe chosen So as to be TepfeSentedby point 1 of the anneXed dfawing.

4. A 1111id aqueoUS aTnInoniated pigInent coating con1- position foTWateT-1aid ce11uloSe vebS. Which conSistS es sentia11y of a uniforn1S11Spension of a hydTophi1ic inof ganic fninefal pign1ent as coati ngco1 onent in 3. latex of a hydfophobic organic sI1bstaI1tia11y 7595:4-24:13 peTcent by We ht ethy1 acfy1ate:acry1onitri1e:Inethacry1ic acidcopolyIneT aS adhesive con1ponent thefefof, Said po1y- Iner beingforn1ed by copo1yInefization of said ethy1 acrylate. acTylonitfile andn1ethacfylic acid iI1 aqueonS nedi un1 containing a SodiUn C C dia1ky1SI11foSUCCinate aS eInI11Sifying agont and Suicient aII1IT1oniun1hydfoxide to ive said com osition a H of at least 9. the vvei ht of Saidpign1ent being 5 to Z0 tinles the Weight of said polymer.

5. A compoSition accofding to claiIn 4 WheTein tho sodiun1 C C dialky1SI11foSuccinate is Sodium di(1.3-d1' nlethylbuty1) Sulfosuccinate.

6. A coIIlposition accoTding to clain1 4 vVheTei11 the SodiIIn1 C Cdia1ky1 Su1fosuccinate iS Sodi11I1 di(1 Inethylbuty1) SU1foSuccilate.

7. PapeT carrying on at 1eaSt one side a coating con1- position in d1iedState accoTding to c1aiIn 1.

1efeTe11ces (:ifed by fhe =xan11ne1 UNTTED STATES PATENTS 2,889,299o/1959 Ritson 26029.6 3,004,938 10/ 1961 ChafnbeTS et a1 26029.6

MURRAY TLLMAN. Prmr Exm.

I. ZEIGLER, m Exer.

1. A FLUID AQUEOUS AMMONIATED PIGMENT COATING COMPOSITION FOR WATERLAIDCELLULOSE WEBS, WHICH CONSISTS ESSENTIALLY OF A UNIFORM SUSPENSION OF AHYDROPHILIC INORGANIC MINERAL PIGMENT AS COATING COMPONENT IN A LATEX OFA HYDROPHOBIC ORGANIC SUBSTANTIALLY 75-95:4-24:1-3 PERCENT BY WEIGHTETHYL ACRYLATE:ACRYLONITRILE:METHACRYLIC ACID COPOLYMER AS ADHESIVECOMPONENT THEREFOR, AND SUFFICIENT AMMONIUM HYDROXIDE TO GIVE SAIDCOMPOSITION A PH OF AT LEAST 9, THE WEIGHT OF SAID PIGMENT BEING 5 TO 20TIMES THE WEIGHT OF SAID POLYMER.